Bicycle wheel with disk cover

ABSTRACT

A bicycle wheel has a plurality of spokes arranged between a continuous profiled rim and a hub (5). At least one covering disk (6) is releasably secured to the wheel in order to provide it with a lateral cover. In order to obtain an easy to release and aerodynamically optimum cover, at least one continuous snapped groove (7) into which the covering disk can snap-in is shaped in the side of the rim profile.

GENERAL DESCRIPTION

The present invention relates to a bicycle wheel with a plurality ofspokes extending between a hub and a rim to which at least one diskcover is removably attached in order to provide the wheel with a lateralfairing.

All types of bicycles (touring, racing, mountain bikes, etc.) have incommon that the energy produced by the rider is largely used to overcomethe air resistance, the driver's frontal area making the biggestcontribution to drag, followed by the wheels.

In order to reduce the effect of the wheels on air resistance, variousembodiments of fully integrated disk wheels have been introduced. Fullyintegrated disk wheels are completely covered on both sides, the diskcover serving as a load carrying element for both tension loads andother kinds of loads during the ride.

Compared to spoked bicycle wheels, the disadvantage of the fullyintegrated disk wheels is their distinctly poor ability to absorb roadshocks. In addition, their rolling performance is noticeably rougherthan that of spoked wheels. Furthermore, due to the disk's stiffness,fully integrated disk wheels produce considerably more noise during theride.

In order to transfer the aerodynamic advantages of a fully integrateddisk wheel to a conventional spoked wheel, the U.S. Pat. No. 4,712,838for instance recommends to provide the spokes adjacent to the rim with anumber of clips by which a disk cover is held in place serving as alateral fairing of the bicycle wheel.

Another method already in use employs a plastic film which is supportedat the hub, stretched and glued at the outer edge to the rim of thewheel, in particular to the rim side walls.

Both the clip disk cover as well as the adhesively joined plastic filmare usually fitted to both sides of the wheel, the spokes remaininginside the fairing.

The disk cover as disclosed in the U.S. Pat. No. 4,712,838 has thedrawback of an air gap formed between the disk edge and the rim, therebyincreasing the air resistance over that of the fully integrated diskwheel. In addition, changing of the disk cover requires undoing numerousfastening elements. Since these are simply clipped to the spokes, theycan get lost. In this case, the disk cover is no longer uniformlysupported along its circumference by the wheel.

Regarding the adhesively joined plastic film cover, damage of theplastic film requires its removal costing time and money. To inflate thetire, access to the valve is rather difficult in both cases.

Therefore, it is the intent of the present invention to improve theremovable fastening of the lateral wheel cover by simultaneouslyproviding the cover with a snug fit on all rim shapes omitting edges,bolts, air gaps or the like.

For a bicycle of the kind disclosed in claim 1 of the U.S. Pat. No.4,712,838, the present invention offers a satisfactory answer to theabove intent by providing the rim laterally with at least onecircumferential catch groove into which the disk cover is engaged.

On the rim the catch groove is formed between the spoke hole side andthe side wall of the rim. A catch groove of this kind can be formed onall types of rims, as for instance aluminum rims, stainless steel rims,hollow cross-section rims or concave flange rims. Catch groove fittedrims can therefore be used with both wire reinforced tires and foldingtires. The disk cover disclosed by the present invention is simplyclipped to the hub and then inserted in the catch groove along its outeredge. Since the catch groove is formed as an integral part of the rim,no additional fastening elements are needed. Neither air gaps nor edgesare produced between the disk cover and the rim and/or rim side wall.The disclosure by the present invention offers a complete lateral wheelcover of optimum aerodynamic design as is usually provided only by thefully integrated disk wheel. At the same time, the bicycle wheeldisclosed by this invention offers all advantages of the spoked wheel.All hub and spoke types in use for bicycles are suitable. Instead ofconventional wire spokes, tensioned high-strength fibers, made ofKevlar, for instance, can be used to connect the hub and the rim.

By completely covering the bicycle wheel, an enclosed interior isobtained which is most favorably protected against humidity, dirt andwear from entering road debris or the like.

At the same time, the rim side walls can be fully used as brakingsurfaces in contrast to the plastic film cover which is glued to the rimside walls. In addition, ease of maintenance and access to the valve ofthe spoked wheel is maintained in contrast to the fully integrated diskwheel and/or the adhesively joined plastic film cover.

A favorable embodiment of the present invention consists of anessentially circular hoop and a cover which is stretched over andretained by the hoop. The diameter of the hoop is of a size whichpermits the disk cover to be engaged easily in the catch groove and tobe held firmly therein during the ride. The so formed wheel covers areeasy to handle and assembled. The center opening of the cover isprovided with a clip ring by means of which the disk cover is installedon the hub. The clip ring fits on the hub flange into which the spokesare inserted.

A preferred embodiment of the present invention consists of a recessedcatch groove located in the section between the spoke hole wall and theside wall of the rim in which the disk cover having an edgereinforcement is engaged and held. This extremely easy method ofinstallation provides a sealed joint between the disk cover edge and therim, keeping the outside surfaces of the rim smooth.

By using an elastic edge reinforcement in the edge of the cover,preferably of circular or tubular cross section, a particularly simpleand elastic joint between the rim and disk cover is obtained enablingquick installation and removal of the disk cover.

On the inside, the outer edge of the disk cover can be provided with aring-shaped web by means of which it is engaged in a respective grooveof the rim.

A simple embodiment of the present invention consists of a catch groovehaving a semicircular shape enabling the disk cover to be securely heldin place and to be easily removed.

Bicycle rear wheels are offset at the hub in order to allow for theaccommodation of multi-speed gear clusters on one side of the wheel. Forrims of offset wheels it is of advantage to have the rim side wall onthe gear cluster side generally parallel to the wheel centerline, whilein the direction of the hub the rim side wall on the opposite side ofthe wheel is outwardly inclined at an acute angle with the centerline.This configuration enables the disk cover to be installed generallyvertically on the sprocket side without interfering with the gearclusters. Whereas on the opposite side of the wheel, the disk cover isinstalled at an inclined angle.

In this context, it is of advantage to have the inclination of the rimside walls parallel with the inclination of the cone-shapedconfiguration of the spokes.

Furthermore, it is advantageous for the installation of the disk coverto have the opening of the catch groove in the straight rim side wallface downward toward the hub, while the opening of the catch groove inthe inclined rim side wall is swiveled or inclined outward.

It is of further advantage when the inclined angle of the catch grooveand the angle of inclination of the rim are essentially identical. Inthis case, extending from the inclined rim side wall at the side wall'sangle of inclination, the disk cover will cover the wheel down to thehub in such a way that there will be neither edges nor irregularities inthe section between rim and disk cover.

In order to enable the spokes to be inserted in the spoke holes betweenthe catch grooves with ease and at a certain angle of inclination, it isof advantage to have the spoke holes in the rim, especially thosebelonging to the spokes of the gear cluster side, offset from thecenterline toward the .inclined rim side wall. In this manner, thespokes can be arranged at a reduced angle of inclination.

A preferred embodiment of the present invention provides for the spokeholes to be arranged offset from the rim centerline on the side of theinclined rim side wall. In addition, it is of advantage to have thespoke inserted in the hole closer to the inclined rim side wall at agreater angle with the spoke hole centerline than the spoke inserted inthe hole closer to the rim centerline. The spoke hole centerline isessentially parallel to the rim centerline and offset toward theinclined rim side wall.

In order to improve the stiffness of a hollow cross-section rim,especially with an asymmetric configuration, it is of advantage toprovide the hollow section with an essentially vertical reinforcing rib.

In addition it is advantageous to have the cover stretched over the hoopprovided with a hollow casing on its inside into which a cord isincorporated for tightening the cover. By means of the tightening cordthe cover can be easily installed on and removed from the hoop. It iseasy to change the cover material, the color of the cover or the coverfor cleaning.

Depending on the cover material used, the tightening cord can beomitted. A thermal treatment can be applied to fasten the cover byshrinking it on.

Another embodiment of the present invention consists of a cover which isglued to the hoop. In this case, the hoop is a flattened ring, one flatside being used to fasten the cover by adhesive bonding.

For the cover material a fabric, a film, a fabric-backed fabric, acoated fabric or the like can be used. The choice of the materialdepends on the conditions of the intended use, i.e., weather, wear orthe like. The hoop is preferably made of a metallic or compositematerial. Due to its elasticity and low weight, titanium is a goodchoice for the hoop. In addition to a flexible material, a compositematerial can be used for the disk cover. In this case, the disk's outeredge is provided with the hoop profile making cover and hoop an integralpart.

Another embodiment of the present invention consists of a profiled disklocated on the inside of the wheel cover concentric with the hub of thewheel. The disk serves for contouring the wheel cover, thereby keepingthe spokes from pushing through the wheel cover.

For easy access to the valve in the rim, it is of advantage to providethe wheel cover with an opening in the valve area through which the tirepump can be inserted.

In addition, it is of advantage to provide a device at least forexpanding the hoop inside the access opening. There is a gap on the hoopand the expanding device is movably mounted to the free ends of the hoopwhich confine the gap. By moving the expanding device the diameter ofthe hoop is adjusted.

For installation, the wheel cover is simply inserted into the respectivecatch groove and fixed in position by expanding the hoop. For removal ofthe wheel cover, the order is reversed. Being actuated, the expandingdevice pushes the free ends of the hoop apart in the direction of thecircumference. For removal of the wheel cover, the expanding device issimply released so that, due to the hoop's elasticity, the free ends ofthe hoop meet.

An interesting embodiment of the expanding device consists of a springelement acting in the direction of the hoop's circumference. Forinstallation of the wheel cover, the spring element is compressed byhand. As soon as the hoop has engaged the catch groove, the springelement is released, thereby expanding and fixing the hoop in position.

Another embodiment of the expanding device consists of a rotatingeccentric disc acting on the free ends of the hoop which are bent inwardin a generally radial direction. By simply turning the eccentric disk,the free ends adjoining the disk are expanded, whereby the hoop is fixedin position in the catch groove.

A still further favorable embodiment of the present invention comprisesthe free ends of the hoop which are bent inward in a generally radialdirection and away from each other as well as an expanding device whichconsists of a wedge designed to slide along the free ends of the hoop.The free ends are increasingly spaced apart in the direction of thecenter of the disk cover so that they are pushed apart when the wedge ismoved toward the rim. By moving the expanding wedge along the free endsof the hoop, the disk cover can be fixed in position and/or removed inan easy manner.

In order to form a simple valve access opening and to hold and securethe free end of the loop in an easy manner, it is of advantage toprovide an essentially U-shaped elastic frame to confine the accessopening in the disk cover and to insert the free ends of the hoop in theU-legs of the frame, while the expanding wedge is slidingly arrangedbetween the U-legs. With the help of the frame, the disk cover isfavorably protected against damage or tearing at the access opening. Bysecuring the free ends inside the U-legs, they are not in direct contactwith the cover, thereby being prevented from damaging the cover.Moreover, damage to the free ends of the hoop is thereby avoided. Theexpanding wedge being arranged between the U-legs, the hoop can beeasily adjusted by sliding the wedge toward the rim.

In this context, it is of particular advantage to have the expandingwedge and the U-legs provided with a tongued and grooved joint. Forexample, the expanding wedge can be fitted with two lateral grooves intowhich are engaged the respective tongues on the inside of the U-legs. Inthis manner, the expanding wedge is securely held in place, especiallyin its fully expanded position when it is tangent to the rim. Havingbeen released from its position, the expanding wedge can be removed fromthe frame depending on the depth of the engagement.

In order to easily secure the expanding wedge in its expanded position,it is of advantage to provide the U-legs with a lug. Provided withcorresponding projections, the expanding wedge engages this lug. It issafely secured due to the elasticity of the frame.

In order to easily seal the access opening, it is of advantage if a lidis pivotably fastened to the end of the expanding wedge opposite therim. In its fully extended position, the expanding wedge and the lidwill seal the access opening completely.

Furthermore, it is of advantage to arrange the lid and the expandingwedge flush with the wheel cover, thereby avoiding edges which increasedrag.

An easy way to fasten the lid is to fit it with a snap nose whichengages the web of the U-frame by gripping around it, thereby holdingthe lid in position.

For easy handling of the lid, it is of advantage to provide it with afingerhole. By inserting a finger, for example, the lid is pivotedoutward, thereby also allowing the removal of the expanding wedge fromits expanded position.

The rim is jointed to a circular hoop with a closely fitting pluginserted at the joint. The thereby increased mass at this point of therim causes a certain imbalance. In order to restore wheel balance to acertain extent, it is advantageous to locate the valve access openingdiametrically opposed to the rim joint.

Furthermore, it is favorable, if the U-shaped frame, the expandingwedge, and the lid supply essentially the weight necessary to balancethe wheel which is unbalanced by the rim joint. By doing so, there is noneed for additional balancing of the wheel.

For easy removal of the completely closed hoop from the catch groove, apreferred embodiment of the hoop is provided with at least oneindentation oriented away from the catch groove, which helps to removethe hoop as if with a lever.

In order to facilitate levering the hoop, it is of further advantage toplace elastic supporting pieces at intervals between the catch grooveand the hoop. In this way, the hoop will react to a radially appliedlever by moving outward in radial direction, thereby facilitating itsremoval.

For spring-actuated closing of the lid, it is of advantage to provide aspring element between the lid and the expanding wedge. The lid isclosed through the force of this spring element and stays closed when aride is started. In this way, starting a ride with an open lid isprevented and safety is increased.

In order to improve load transfer and to reduce peak loads, a preferredembodiment of the present invention consists of beveling the rim jointfaces. The application of a beveled rim joint is not confined to the rimshapes depicted herein. Beveling of rim joints can be used on any typeof rim, such as aluminum rims, stainless steel rims, hollowcross-section rims, concave flange rims or the like.

In order to affect neither the radial stiffness of the bicycle wheel northe performance of the brakes, it is also of advantage, if the beveledface plane of the joint runs across the rim section between the rim sidewalls, the plane's normal meeting the circumferential line at an acuteangle. The joint face is essentially perpendicular to the upper or lowerside of the rim.

In order to further improve stability, it is of advantage to incorporateat least one socket inside the hollow section of the rim, extending atequal length to either side of the rim joint in the direction of thecircumference.

Another advantage is to place the socket face parallel with the rimjoint plane. By doing so, peak loads in the joint area are uniformlydistributed between the joint and the socket.

It is of great advantage, if the hollow section of a rim which has beenpartitioned by a reinforcing rib is fitted with one socket each for eachsubsection.

In order to improve the braking performance of the rim, the wet rim inparticular, it is of advantage to coat the rim side walls with afine-grain ceramic coating. A ceramic coating of this kind can beapplied to any known bicycle wheel. Plasma spraying is one of themethods used.

Due to the different elastic behavior of the ceramic coating and therim, the ceramic coating can chip. To prevent chipping as far aspossible, it is of advantage to provide the ceramic coating with astress-relieving gap concentric with the hub. In general, thestress-relieving gap is located midway on the rim side wall, itsthickness ranging from 0.3 to 0.8 mm.

The disclosures and preferred embodiments of the present invention arefurther described and depicted by the following figures.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 discloses a side view of a rear bicycle wheel;

FIG. 2 discloses line II--II of FIG. 1 in cross-section;

FIG. 3 discloses an enlarged view of detail III of FIG. 2;

FIG. 4 discloses a side view of another embodiment of the presentinvention with an access opening in the wheel cover;

FIG. 5 discloses line V--V of FIG. 4 in cross-section;

FIG. 6 discloses line VI--VI of FIG. 4 in cross-section;

FIG. 7 discloses another embodiment of the expanding device of thepresent invention;

FIG. 8 discloses a side view of another embodiment of the presentinvention;

FIG. 9 discloses line IX--IX of FIG. 8 in cross-section;

FIG. 10 discloses another embodiment of the present invention relatingto FIG. 3; and

FIG. 11 discloses a simplified drawing of a rim as seen from above.

DETAILED DESCRIPTION

FIG. 1 shows a partial side view of a bicycle 2. A rear wheel 1 isrotatingly mounted to the seat stay 8 and the chain stay by means of ahub 5. Not shown are the saddle to which the seat stay 8 extends and thecrank axle to which the chain stay 9 extends.

A great number of spokes 3 are arranged between the hub 5 and thecircular rim 4. For convenience, only a few spokes are shown in FIG. 1.The hub 5 is located in the center of the circular rim 4. On itscircumference, the rim 4 is fitted with the tire 17.

Concentric with the hub 5, a multi-speed gear cluster is provided.Between the hub 5 and the rim 4, a disk cover 6 having a cover 12 isprovided in order to cover the side of the wheel.

FIG. 2 shows a cross-section of the bicycle wheel 1 along line II--II ofFIG. 1. For convenience, the tire 17 mounted on the rim 4 of FIG. 1 hasbeen omitted in FIG. 2.

Both sides of the bicycle wheel are fitted with the disk covers 6between the hub 5 and the rim 4. The disk covers are mounted to thewheel by inserting their outer edge by means of the hoop 11 into thecatch groove 7 of the rim 4. The catch grooves 7 are located on thespoke hole side 22 directly adjacent to the rim side wall 20. The diskcover is provided with a cover 12.

The cover 12 extends from the hub ring 54 holding the disk cover at thehub 5 to the hoop 11. It is stretched around the hoop 11 inserted in thecatch groove 7 and is finished off with a peripheral casing 13 whichcontains the tightening cord 14. On the inside 15 of the disk cover 6,profiled disks 23 are arranged concentric with the hub ring 54. Thediameter of these disks is greater than that of the hub ring 54. Thedisks 23 serve to keep the cover 12 at a distance from the spokes.

The spokes 3 extend between the hub flange 21 and the spoke holes 18located on the centerline of the rim 4. The method used to insert thespokes 3 in the hub flange 21 and to tighten them in the rim spoke holes18 by means of nipples is well known to those skilled in the art.Extending from the hub flange 5, the spokes are more strongly inclinedtoward the vertical 55 than is the cover 12 of the wheel disk 6. Therebyall the spokes 3 stay inside the two lateral disk covers 6.

The tire is mounted on the bed 19 of the rim 4 opposite the spoke holeside 19 and separated from it by the hollow cross section 16. The rimbed 19 and the spoke hole side 22 are interconnected by an aperturewhich enables the spokes 3 to be fastened in the spoke holes 18. On oneside of the bicycle wheel 1, the hub 5 which projects beyond the diskcover 6 is fitted with a gear cluster 10. On this gear cluster side ofthe wheel, both the spokes 3 and the cover 6 are less inclined towardthe vertical 55 than those on the opposite side of the wheel 1.

FIG. 3 shows an enlarged view of detail III of FIG. 2. For convenience,both the spokes 3 and the disk covers 6 of FIG. 2 are omitted.

The rim 4 comprises two fairly straight rim side walls 20 spaced apart.In the section between the spoke hole side 22 and the rim side wall 20,the essentially semicircular catch groove 7 is located. In this section,the rim side walls are extended into a lip 48 which confines the catchgroove 7. The spoke hole 18 is located on the centerline between thecatch grooves 7 and between the rim side walls 20. It is connected tothe rim bed 19. The hollow section 16 extends between the rim bed 19 andthe spoke hole side 22. The rim bed 19 is laterally confined by the rimside walls 20 which, fitted with hooked edges, serve as mountingsupports 49 for tires, wire-reinforced tires for instance.

FIG. 4 depicts the bicycle wheel 1 with the rim 4 and the disk cover 6.Located in the rim bed 19 is the valve 25. It projects from the spokehole side of the rim 4 and is accessible through the opening 24.

The hoop 11 is inserted in the peripheral catch groove 7, partiallydisappearing therein. In the vicinity of the valve, there is a gap inthe hoop 11 so that the catch groove is visible. The free ends 28 and 29of the hoop 11 are bent toward the center of the wheel and are more orless parallel to each other.

In order to confine the valve access opening 24 and the free ends 28 and29, an essentially U-shaped frame 35 is provided within the cover 12 ofthe disk cover 6. Its U-legs 36 point toward the rim 4, the U-web 37being arranged at a right angle to the free ends 28 and 29. The U-legs36 and the free ends 28 and 29 are of essentially the same length, thefree ends being inserted into the opening of the U-legs 36.

The U-legs 36 increase in thickness toward the rim 4, the legs beingessentially straight on the outside, but sloped on the insideapproaching each other toward the rim 4.

On the inside of the opposing U-legs 36, a wedge-like expanding deviceis slidably arranged, its width decreasing in the direction of the rim4. By sliding the wedge 34 radially toward the circumference of thewheel 1, the U-legs 36 including the free ends 28 and 29 of the hoop 11are expanded in the direction of the circumference 31. When the end 30of the wedge comes into a close fit with the catch groove 7, it assumesits fully expanded position. In order to secure this position, theinside of the U-legs 36 are fitted with lugs 39 which interlock with therespective projections of the wedge 34.

A lid 40 is provide between the expanding wedge 34 and the web 37 of theU-shaped frame. It seals the valve access opening 24 in conjunction withthe expanding wedge 34.

The lid 40 is fastened to the wedge 34 by means of a pin 41 enabling thelid 40 to pivot. The spring element 44 is arranged coaxially with thepin. It actuates the lid 40 to close in the direction of the web 37 ofthe U-shaped frame.

For handling, the lid 40 has a fingerhole located approximately in thecenter thereof. The lid 40 is provided with a small tab 51 shaped to fitthe U-web 37.

FIG. 5 shows a cross section along line V--V of FIG. 4. The valve 25 islocated in the valve stem hole 50 of the rim 4. Similar to the spokeholes in FIG. 3, the valve stem hole 50 is positioned on the centerlineof the rim 4.

The outer surfaces of the expanding wedge 34 and the lid 40 are shapedto be flush with the rim side walls 20. The end 30 of the expanding edge34 is engaged in the catch groove 7. The pin 41 is situated between thelid 40 and the expanding wedge 34.

The position of the expanding wedge 34 shown in FIG. 5 depicts the lid40 in its fully closed position. The small tab 51 fits the web 37 of theU-shaped frame 37 on one side, while the snap nose 42 projecting fromthe lid 40 engages the web 37 on the opposite side. By means of thespring element 44 shown in FIG. 4, the lid 40 is forced to close in thedirection 47.

The fingerhole 43 is positioned on the outside of the lid 40approximately midway between the small tab 51 and the pin 41. It givesaccess to a finger rest 56 inside the lid 40 which is oriented towardthe web 37 of the U-shaped frame.

FIG. 6 shows a cross section along line VI--VI of FIG. 4. The expandingwedge 34 has a flat oval shape and the width 52. The sides are providedwith grooves in order to engage the U-legs 36. The free hoop ends 28 and29 are fed into the U-legs 36. They have a flat oval cross-section inorder to be prevented from twisting inside the U-legs 36.

The width 52 of the expanding wedge 34 is less than that of the valveaccess hole 24 at the level of the fingerhole 43 as shown in FIG. 4.Therefore, the expanding wedge 34 together with the lid 40 is removablefrom the valve access hole 24, if pushed far enough toward the web 37 ofthe U-shaped frame.

FIG. 7 depicts another embodiment of an expanding device. The free hoopends 28 and 29 confine a gap of the width 53 and are facing each other.A spring element 32 is located between the free ends by means of asleeve 33. The free ends 28 and 29 are partially fed into the sleeve 33and can be adjusted in relation to it.

FIG. 8 depicts another embodiment of the bicycle wheel 1 as disclosed bythe present invention. The hoop 11 retaining the cover 12 is inserted inthe catch groove of rim 4, thereby covering the bicycle 1 laterally withthe disk cover 6. At one point of its circumference, the hoop 11 isprovided with a dent 45 for handling. It is formed by bending a segmentof the curved hoop 11 to the inside of the hoop.

A further embodiment of the present invention permits to place a numberof elastic supporting elements 46 at intervals around the catch groove.

FIG. 9 shows a cross section along line IX--IX of FIG. 8 to illustratethe supporting elements. A supporting element 46 is located in the catchgroove 7 of the rim 4, thereby providing a resilient support for thehoop 11.

FIG. 10 shows another embodiment of the rims disclosed by the presentinvention and the description of FIG. 3. The rim 4 is provided with therim bed 19 serving as a mount for a tire which is not shown. Accordingto the description of FIG. 3, the tire is mounted between the hookededges of the rim walls 20 and 20' and held in place by the tire mounts49.

The vertical centerline 55 is shown to extend between the upper part ofthe rim side walls or tire mounts 49 respectively.

The rim side wall as shown on the right side of FIG. 10 lies essentiallyparallel to the centerline 55, whereas the inclined rim side wall 10',upon extension of its line of inclination, makes an acute angle 63 withthe centerline 55. In the direction of the hub as shown in FIG. 2, therim side wall 20' is inclined outward. On the side of the essentiallyparallel rim wall 20, the multi-speed gear wheels 10 are mounted on thehub 5 as shown in FIG. 2.

As a whole, the rim 4 is asymmetric in relation to the verticalcenterline 5. The catch groove 7 to the right side of the centerline 55has an essentially semicircular cross section. The pertaining center anddiameter of the semicircle are located on the horizontal 65. The catchgroove 7' to the left side of the centerline 55 has also as essentiallysemicircular cross section. The pertaining center and diameter of thesemicircle are located on a line which is inclined upward relative tothe horizontal 65 at the angle 63. The center of the catch groove circleis located at the intersection between the horizontal 65 and the lineinclined at the angle 62. Both catch grooves 7 and 7' are extendedbeyond the horizontal line 65. The extensions are essentially tangent tothe circle line of the catch groove and are given a curving forintegration with the spoke hole side 22 nd the rim side walls 20 and20'.

The hollow cross section 16 is located between the catch grooves 8 and7' the spoke hole side 22 and the rim bed 19. On the side of the catchgroove 7, to the right of the center line 55, the hollow section isreinforced with an essentially vertical rib 57.

The reinforcing rib 57 divides the hollow section into two parts. Theresulting smaller hollow section is located above the catch groove 7,the larger hollow section above the catch groove 7', both extendingacross the spoke hole side 22 of the rim. The wall thickness of thespoke hole side below the larger hollow section is greater than thatbelow the smaller hollow section. There is a transitional zone under thereinforcing rib 57. On the spoke hole side 22 adjacent to the catchgroove 7, a recess is provided in order to save material.

The spoke holes 18 and 18' are offset from the vertical centerline 55towards the catch groove 7'. They are successively arranged in the rimaccording to common practice. The spoke 3 enters the spoke hole 18 atthe acute angle 61 with the spoke hole centerline 58 being given anoutward inclination on its way toward the hub. The spoke 3' enters thespoke hole 18' at the acute angle 60 with the spoke hole centerline 58being given an outward inclination on its way to the hub. The spokes 3and 3' diverge in the direction of the hub 5 shown in FIG. 2. They arehooked in the hub flange 21 according to common practice.

The spoke hole centerline 58 lies parallel to the vertical centerline 55from which it is offset at a distance 59 toward the inclined rim sidewall 20'. The acute angle 60 enclosed between the spoke 3' and the spokehole centerline 58 is slightly bigger than are the acute angles 62 and63 which are equal. The size of the angles depend among other things onthe wheel diameter and the offset 59 between the spoke hole centerline58 and the offset 59 between the spoke hole centerline 58 and thevertical rim centerline 55. For the embodiment of the present inventiondisclosed in FIG. 10, the angle 60 is essentially twice as big as theangle 61.

The ceramic coating 66 and 67 is shown to cover the surface of the rimside wall 20. It is divided into two equal sections which are spacedapart by the stress-relieving gap 68 by 0.3 to 0.8 mm. Thecircumferential gap 68 is located midway on the rim side wall 20, thecoating sections extending equally far to either side of the gap in thedirection of the vertical centerline 55.

For convenience, the corresponding ceramic coating on the opposite rimside wall 20' is omitted in the figure.

FIG. 11 shows a simplified view of the rim 4 depicted in FIG. 10 as seenfrom above in the direction of the rim bed 19. It illustrates the joint76 of the rim 4. The joint is defined by the face plane 76 which extendsacross the rim 4 between the two rim side walls 20 and 20' the plane'snormal 77 meeting the circumference 31 at an acute angle. The rim jointplane is essentially vertical between the rim bed 19 and the spoke holeside 22 shown in FIG. 2.

The sockets 70 and 71 are inserted into the hollow section 16 shown inFIG. 10 and/or are inserted into the hollow sections partitioned by thereinforcing rib. They can be made to match the shape of the partitionedhollow sections enabling their installation by a pressed fit. The faces72 and 73 and/or 74 and 75 of the sockets 70 or 71 are parallel with theplane of the rim joint 69. The rim joint 69 is shown to not betransverse with the sides of the rim, i.e. it is beveled. As a result,the cross section of the sockets 70 and 71 is shaped like aparallelogram, the longer sides being parallel to the rim side wall 20or 20' and the reinforcing rib 57. The shorter sides, i.e., the faces,being located at an approximately equal distance from the rim jointplane 69.

For a hollow cross section rim 4 without reinforcing rib 57, i.e., thehollow section being a single unit, the socket is a one-piece element,as a rule.

We claim:
 1. A wheel (1) for a bicycle (2) having a plurality of spokes(3) arranged between a circumferential rim (4) and a hub (5), having afirst and a second disk cover (6) removably mounted thereto to cover thewheel laterally, said rim (4) being laterally provided with first andsecond circumferential catch grooves (7;7') for the respective diskcover (6) to be inserted in said groove;said wheel further including arim side wall (20), an inclined rim side wall (20'), and a spoke holeside (22), said first catch groove (7) being circumferentially locatedin the section between said rim side wall (20) and said spoke hole side(22), and said second catch groove (7') being circumferentially locatedin the section between said inclined rim side wall (20') and said spokehole side (22); said catch grooves (7,7') holding in place saidrespective disk cover (6) with an edge means (11) inserted under tensiontherein; and said catch groove (7') assigned to said inclined rim sidewall (20'), is inclined outward at an angle (63) in relation to saidcatch groove (7) of said rim side wall (20).
 2. The bicycle wheel ofclaim 1, wherein said angle (63) and the angle of inclination (62) areessentially equal.
 3. In a wheel (1) for a bicycle (2)a circumferentialrim (4) having an outwardly facing bed for receipt of a tire, twooppositely disposed sidewalls and an inner wall opposite to said bed,said inner wall being equipped with a plurality of spoke holes, a hub(5) centrally disposed relative to said rim and equipped with aplurality of spoke holes, a plurality of spokes (3) extending betweensaid rim and hub and being secured in said rim holes and hub holes, saidhub, spokes and rim defining said wheel and with said wheel havingsides, at least one catch groove (7) extending circumferentially in saidrim inner wall adjacent said spoke holes and being open in the directionof said hub, a disk cover (6) covering one wheel side and having acircumferential edge means (11) received in said groove, said edge meansexerting an outwardly directed tension; said disk cover (6) consistingof an essentially circular hoop (11) and a cover (12) stretched oversaid hoop, an access opening (24) being provided in said disk cover (6)in the vicinity of a valve (25) into which an expanding means (26, 32,34) is incorporated at least for expanding said hoop (11), said hoophaving a gap (27), and said expanding means being movably interlockedwith the free ends (28, 29) of said hoop (11) which confine said gap,said free ends (28, 29) are essentially bent inward in a radialdirection and away from each other, and said expanding means (26, 32,34) consists of an expanding wedge (34) slidingly arranged on said freeends.
 4. The bicycle wheel of claim 3, and wherein an essentiallyU-shaped elastic frame 35 is provided to confine the access opening 24in said disk cover 6, and said free ends (28, 29) of said hoop 11 arefed into said U-legs (36) of said frame, said expanding wedge 34 beingslidingly arranged between said U-legs.
 5. The bicycle wheel of claim 4,wherein said expanding wedge (34) and said U-legs (36) are provided witha tongue and groove interlock.
 6. The bicycle wheel of claim 4, whereinsaid U-legs (36) are provided with a tongue (39) for fixing saidexpanding wedge (34) in its expanded position.
 7. The bicycle wheel ofclaim 4, wherein said U-frame (35), said expanding wedge (34), said lid(40), and said valve (25) supply essentially the weight needed tobalance the wheel which is unbalanced due to said rim joint.
 8. Thebicycle wheel of claim 3, wherein a lid (40) is pivotably fastened tothe end 30 of said expanding wedge opposite said rim 4, said lid andsaid expanding wedge when in its expanded position sealing said accessopening (24).
 9. The bicycle wheel of claim 8, wherein said lid (40) andsaid expanding wedge (34) are arranged flush with said disk cover (6).10. The bicycle wheel of said claim 8 or 9, wherein said lid 40 isprovided with a snap nose (42) for engagement with the web (37) of saidU-shaped frame (35).
 11. The bicycle wheel of claim 8 or 9, wherein saidlid is provided with a fingerhole (43).
 12. The bicycle wheel of claim 8or 9, wherein a spring element 44 is arranged between said lid 40 andsaid expanding wedge 34 for spring-actuated closing of said lid in afirst direction (47).
 13. The bicycle wheel of claim 4 or 8, whereinsaid valve access opening 24 is located diametrically opposed to the rimjoint of said rim (4).
 14. In a wheel (1) for a bicycle (2) having aplurality of spokes (3) arranged between a circumferential rim (4) and ahub (5), having at least one disk cover (6) removably mounted thereto tocover the wheel laterally, the improvement comprising the rim (4) beinglaterally provided with at least one circumferential catch groove 97)for the disk cover (6) to be inserted in said groove, said disk cover(6) consists of an essentially circular hoop (11) and a stretchablecover (12) over said hoop, said hoop is completely closed and isprovided with an access dent (45) facing away from said catch groove (7)at least at one point.
 15. In a wheel (1) for a bicycle (2)acircumferential rim (4) having an outwardly facing bed for receipt of atire, two oppositely disposed sidewalls and an inner wall opposite tosaid bed, said inner wall being equipped with a plurality of spokeholes, a hub (5) centrally disposed relative to said rim and equippedwith a plurality of spoke holes, a plurality of spokes (3) extendingbetween said rim and hub and being secured in said rim holes and hubholes, said hub, spokes and rim defining said wheel and with said wheelhaving sides, at least one catch groove (7) extending circumferentiallyin said rim inner wall adjacent said spoke holes and being open in thedirection of said hub, a disk cover (6) covering one wheel side andhaving a circumferential edge means (11) received in said groove, saidedge means exerting an outwardly directed tension; said rim (4) has abeveled joint (69) defined by faces (72, 73) with said faces beingparallel with the plane of the rim joint; and a joint plane (76) extendsacross said rim 4 between said rim side walls (20, 20') and said planemeets the circumference (31) at an acute angle.
 16. The bicycle wheel ofclaim 15, wherein in the rim joint area (76) there is at least onesocket (70, 71) inserted inside the hollow cross section (10) andextending essentially at an equal length to either side of said rimjoint (76) in the direction of the circumference (31).
 17. The bicyclewheel of claim 16, wherein the faces (72, 73, 74, 75) of said sockets(70, 71) are essentially parallel to said rim joint plane (76).
 18. Thebicycle wheel of claim 16, wherein one each of said sockets (70, 71) isinserted in one of the subsections obtained by dividing the hollow crosssection by said reinforcing rib (57).